For a small ship the waves are high and staying on the deck is difficult.

Click Here the DD-869 approaches the USS Kitty Hawk for refueling.
When these ships refuel, the tanker / supply ship comes along side the
aircraft carrier.
The fuel lines are connected between the two ships.
Next, the destroyer comes along the other side of the tanker.
This
way the tanker refuels both ships at the same time making a quick job of
at sea refueling.
While the ships are in the refueling position,
supplies are transferred between the ships.
The most favorite supply
is Soda and Fresh Milk.
This entire process of refueling and
re-supply is called an Un-Rep which stands for underway replenishment.

When I was in the navy,

I thought this operation was called an On-Rep because we took supplies
on to the ship.
I also thought there was an Off-Rep, I was wrong,
there were no such names as on-rep and off-rep.
Thanks to the readers
of these pages I have been corrected and educated a little more.
C. Jeff Dyrek, webmaster